Calibration device and calibration method

High precision calibration of external parameters is possible even when the surrounding road surface is configured from a plurality of flat surfaces. Specifically, provided is a calibration device comprising a camera to be mounted on a vehicle traveling on a road surface; a characteristic point extraction unit which extracts characteristic points from a captured image obtained by being captured with the camera; a tracking unit which tracks the characteristic points extracted with the characteristic point extraction unit; a storage unit which stores a trajectory of the characteristic points obtained by tracking the characteristic points; a road surface estimation unit which estimates a flat surface on which the vehicle is traveling by using the trajectory of the characteristic points; a calculation unit which calculates a calibration trajectory, which is a trajectory of the characteristic points, for use in calibration based on the estimated flat surface; and an external parameter estimation unit which executes calibration of an external parameter of the camera by using the calibration trajectory.